Reciprocating motor



March 24, l931- c. s; WEYANDT REGIPROCATING MOTOR Filed July 9. 19274VSheets-Sheet l )jy/N701? @Lw a A TTORNEY Irl KN "7% N March .24, 1931.c. s. WEYANDT RECIPROCATING MOTOR Filed July 9, 1927 4 Sheets-Sheet 2 uA TTORNE Y MalCh 24, 1931. c. s. WEYANDT RECIPROCATING MOTOR l FiledJuly 9. 1927 4 Sheets-Sheet 3 JNVENTO/e $5. 6%/ z A TTORNEY March 24,1931.

C. S. WEYANDT RECIPROCATING MOTOR yy NTR NEY 1 A' TTOR Patented Mar. 24,19311'.

UNITED .STATE-1S PATENT oFFlcl.v

BECIPROGATING Moron application mea July 9, 1927'. serial No. 204,510.

, My invention relates to reciprocating electric motors or hammers, andto systems for cooling and controlling the same, the motors or hammersbeing utilizable for any suitable f purpose andparticularly aspercussive tools for drilling, cutting, chipping, riveting or otherwiseworking metal, stone, concrete and the like, and for 'tamping railwayballast or ties, earth and other materials.

In accordance with my invention the electric reciprocating motor `orhammer is constructed and its parts arranged'to afford passages,including ducts outside of and within the winding-or windings, throughwhich a cooling medium, as air or equivalent, is passed.

Further in accordance with my invention, a portable'reciprocatin motoris comprised in a system with a portable power plant comprising a sourceof current and a pumpor cooling medium; and more particularly the systemmay comprisel also a portable control box, intervening between the powerplant andreciprocating motor,` in which may be disposed the pump withits driving motor and such other and `:further .devices as may bedesired.

Further in accordance with my invention there is provided a pump forcooling medium driven by an electric motor which is controlled eitherbya switch uponpthe reciprocating motor or hammer for causing operation ofthe pump only when the hammer is in operation, or by -a'separate switchWhereby the pump may be continuously driven.

Further in accordance with my inventionY there is provided a controlunit or box in which are disposed the electric valve structure and theblower or air pump and its driving motor and upon which is mounted oneelement of an electric and air coupling which constitutes a terminal ofan air hose with which are associated conductors extending to thereciprocating motor.

Further in accordance with my invention, the pole tips of the magneticfield members are hardened and ground iush with the supporting member orbarrel and come into direct magnetic contact with the reciprocating coremember which bears upon them.

My invention resides in a system, features of construction, arrangementand combinations thereinafter described and claimed.

This application is impart a continuation of my application Serial No.708,209,led April'22, 1924.

Forv an illustration of one of the various forms my invention may take,reference is to be had to the accompanying drawings, in which:

Fig. 1 is a longitudinal section,'some parts in elevation, of areciprocating electric motor embodying my invention.

Fig. 2 is a cross-sectional view, parts in elevation, taken on the line2-2 of Fig. 1.

Fig. 3 is a cross-sectional view, parts in elevation, taken on the line3-v-3 of Fig. l.

Fig. 4 is a cross-sectional view,parts in elevation, taken on the line4--4 of Fig. 1.

Fig.` 5 1s a cross-sectional view, parts in elevation, taken on the line5-5 of Fig. 1.

Figs. v6 and 7 are developed plan views of pole tips and slotted barrel.

Fig. 8 is a diagrammatic view of the electric and `air control system. AFig. 9 is a top plan view ofthe control unit or box, with cover removed.u

- Fig. 10 isa vertical sectional view, parts in elevation, of thecontrol box or unit. Y Fig. 1l illustrates a reciprocating motor systemembodying my invention.

Fig. 12 is a diagram of a circuit arrangement utilized in controllingenergization of the reciprocating motor.

Fig. 13 is a fragmentary perspective view of the cable effecting air andelectric connections between the reciprocating motor and the generatorand blower of the power plant.

Fig.'14 is a side elevational view, partly in section, of an air andelectric cable or hose coupling.

Fig. 15 is a fragmentary elevational view of a hollow tool utilizablewith the reciprocating motor.

Referring to the drawings, 1 is a barrel o1' a tubular guide member, ofmetal, such as brass or bronze, or light weight alloy such 'as anysuitable alloy ot aluminum. VDisposed upon the exterior of the member l,and abutting against its flat surfaces, are the circumferenter abuttingagainst or closely approaching the inner wall of the enclosing caslng ofsuitable magnetizable material such as silicon steel and substantiallyclosed to the atmosphere. .The axially extending portions of the laminaehave pole-trips' 6, 7, 8 and 9 extending through openings in thebarrel 1. These pole tips are preferably hardened by any suitableprocess, such as case hardening, for a distance of about inch back fromvtheir inner edges Where they are preferably ground flush with'theinner. surface of the barrel 1 which is also preferably simultaneouslyground whereby there is provided an accurate bearing for thereciprocating core member 10 of magnetizable material having welded orotherwise attached thereto at its ends the members 11 of non-magneticimpact 'esisting material, such as stellite or equivaent.

The hardened pole tips providey a hard wearing surface which greatlyincreases the life of the motor or hammer sometimes to the order ofthreefold; and the extremely close approach to or direct contact withthe core 10 materially increases the efticiency of the hammer, usuallyto the order of 30%. y

The clamps 12, held to the barrel 1 by screws 13, at their beveled edgesengage the beveled ends of axially neighboring groups of laminaeclamping them to the barrel 1. Surrounding the laminae and their clampsare the solenoids or motor windings 14 and 15.Y

Threaded upon the opposite ends of the barrel 1 are the annular nuts 16whose somewhat beveled ends engage the end groups of laminae. Thelaminae, the windings 14 and 15, and the barrel 1 constitute astructural unit which may be assembled as such prior to introductioninto the casing 5 or before vthe assembly of the structure as a whole.

Abutting against opposite ends of the casing 5 are the housings 17 and18 constituting respectively the rear closure or handle member 17 andthefront end closure member 18 which are drawn to each other by bolts 19,Figs. 2

and 5, thereby'clamping the casing 5 and the magnetic field unit betweenthem.

On its forward stroke the core 10 strikes the end or shank 20 of a toolfragmentarily indicated at 2-1. The shank 20 is disposed within abushing 22 having a shoulder held against the left end ofthe barrel 1,Fig. 1, and centered within the hub or'central bushing 23 of the closuremember 18 which has a shoulder abutting against the nut 16.

Extending into the opposite end of the barrel 1 is the bushing 24 havingthe iiange 25 abutting against the ends of the barrel 1 and nut 16.Disposed in the bushing 24 is the anvil or backstop member 26 resistedupon the back stroke of the corel() bythe spring 27, contained withinthe chamber 28, having air hole 28a, and by the spring plates 27 a whoselateral ends are held by the bolts 19.

The end closure member 17 is provided with a transversely extending handgrip tubular member 29 adjacent which is the digitally controlledtrigger 30 which controls the co-action of the switch elements 31. yThemember 17 has the inclined hollow portion 32 to whose tree end isconnected lexible air hose or conduit 33 through which extend theseveral conductors communicating with the switch 31 and with thewindings 14, 15.

Air is delivered through the hose 33 through the interior of the member32 to the annularor circumferentially extending chamber 34 in the member17. The air proceeds from the chamber 34 through the spaces 35, Fig. 2,between the groups of laminas 2, through the passages 36, between thewinding 14 and the casing 5, thence through the spaces between the outerends of the groups of laminae 4, thence through the passages 37, betweenthe winding 15 and the casing 5, thence through the spaces between theouter ends of the groups of laminae 3, into the chamberor annularpassage 38 within the end closure member 18` and thence to' atmospherethrough the ports 39. l

Air is delivered also from chamber 34 through the spaces 35, Fig. 2,between the groups of lamin 2, through the passages 36a,

Figs. 4 and 3, between the winding 14 and the barrel 1, thence throughthe spaces between the groups of laminae 4, thence through passages likepassages 36a between the winding 15 and the barrel l, thence through thespaces between the groups of lamina@ 3 into the chamber 38, and thenceto atmosphere.

There are air passages and currents of air therefore both outside of andinside or through the windings 14 and 15. Substantially none of thecooling air passes into or through the barrel or tubular member 1 inwhich may be disposed lubricating material for the core member 10 whichvbears on the hardened pole tips and upon barrel 1.

The barrel or tubular member 1 may be circumferentially closedthroughout its length, though in such case there will be caused thereineddy current losses which may be reduced by utilizing for the member orbarmaterial, thusisolating the interior of the barrel 1 from the aircooling passages whereby escape of lubricantI from the barrel isprevented and whereby entry into the barrel of dust, grit or the like,carried by the cooling air is pre-vented.

r, as indicated in Fig. 7, the slots 40 may be filled withnon-conducting m'aterial 42 of any suitable character, preferably oneunaffected by lubricant in the barrel 1.

Referring to Fig. 8, conductors 43 and 44 represent generically anysuitable source of alternating current of any suitable frequency,including the frequencies of ordinary lighting or power circuits of fromabout 25 to about cycles per second.

In the example illustrated the source of power is the alternatin currentgenerator G, having a suitable field-exciting generator, .driven by anysuitable motor E such as an internal combustion engine, as indicated, oran "electric or other motor, comprising with the generator G a portablepower unit.

As indicated, the generator G may be of the two-phase type whose brushes45 and 46 are connected to conductors43 and 44. A system similar to thatdescribed herein may be operated by connection to the conductors 43 and47 of the other phase, connecting respectively to the brushes 45 and 48.

V and V1 represent generically asymmetrical electrical conductors orelectric valves. In the example illustrated they are of the thermonictype, each comprising an anode a and a filament or cathode f.

A step-down transformer T has its primary winding P connected across theconductors 43 and 44 and its secondaries S and `Sl connected in circuitwith the cathodes f which are rendered incandescent by the currenttraversing t em.

` The conductor 43 is connected to the cathode f of the tube V and tothe anode 0: of the tube V1. The conductor 44 connects with the contactor terminal 49 of the air and electric socket A. The socket A isprovided further with the contacts 50, 51. and 52. The anode a of thetube V connects with the contact 50 and cathode f of the tube V1connects with the contact 51. The conductor 43 connects to one terminalof the rotary electric motor M comprising rotor `or armature 6 and fieldwinding c, and the other terminal ofthe motor M connects to the doublethrow-switch d for connecting, in the position indicated, the motor M tothe contact 52 and in its other position through contact e directly withthe conductor 44. A plug B, on the hose 33, is adapted for attachment inthe socket A by bayonet joint or equivalent means which locks it inpredetermined relation to the socket.

, The plug B carries the contacts 49a, 50a,

51a and 52a which engage respectively the socket terminals 49, 50, 51and 52. On the other end of the hose 33 is a plug B1 adapted to engageby bayonet joint or equivalent in i spectively by the contacts 496, 506,516 and 526. The contact 49d is connected to one terminal of the switch31; the contact 50d connects with one terminal of the hammer Winding 14;contact 51d connects with one terminal of thehammer winding 15; and theother terminals ofthe windings 14 and 15 connect with the other terminalof the switch 31 and with the contact 52d.

When the fin er-opera-ted trigger'switch 31 is closed am? when theconductor 43 is positive, current flows from that conductor from anode ato cathode 7' of the tube V1 and thence through contacts 51, 51a,conductor 510, contact 516, contact 51d, through hammer winding 15,thence through the switch 31 to contact 49d, contact 496, conductor 49e,contacts 49a and 49 to conductor 44, energizing the coil 15 to cause aforward stroke of the core 10 to cause it to impact against the toolshank 20. With the switch 3l closed and the conductor 44 positive,current passes through contact 49, the intermediate contacts andconductors, through the switch 31, through the winding 40 to contact 40dand thence to contact 50 to anode a. of the tube V to its cathode f toconductor 43, thereby energizing the winding 14 to cause a. back-strokeof the core 10. The windings 14 and15 are alternately e11- ergized tocause rapidly recurrent strokes of core 10 so long as switch 31 remainsclosed.

The motor M drives the air pump P which delivers air through the socketA, plug B, hose 33, plug B1, socket Al, and the air passages of theelectric hammer or recipro eating motor as hereinbefore described.

lVith the switch l in the position indicated the motor M is controlledby the trigger switch 31 upon the hammer or reciprocating motor and theswitch 31. simultaneously controls delivery of current through theelectric valves to the windings 14 and 15 as above described.

The motor M and pump P will continuously operate, independently ofcontrol by y switch 31, when the switch Z is thrown onto contact e.

The pump P may be of any suitable character, but is preferably' of therotary or centrifugal type. It may compress atmospheric t case air willbe drawn from the atmosphere l through the apertures 39, and thencethrough the air passages of thel reciprocating motor or hammer throughthe hose and socket A to the intake of the pump P.

It is preferred, as indicated in Fig. 8, that the hammer orreciprocating motor be pro- Y vided with an air and electric socket A1adapted to receive the air and electric plug Bl on the hose. Asindicated in Fig. 1, however, the hose 33 may be directly clamped orsecured to the tube or conduit-..32 and the electric conductorsextending through the hose may connect directly to terminals disposedwithin the housing or handle structure 17.

The hose 33 may be of any suitable structure, but preferably is of thearmored type. F or example, it may comprise inner and outer layers ofrubber-like material between which may be disposed a metallic armor orreinforcing structure.

The conductors 490-520 may be imbedded in the wall of the hose 33 or, asindicated,

extend freely through the hose passage. In

either case, these conductors are longer than the hose or hose passageso that they shall not be placed under substantial tension either whenthe hose is twisted, bent or coiled or,

and principally, when the hose stretches or increases 1n length, as itgenerally does aftery a period of use.

l Vhile the valves V, V1, motor M, pump or blower P and transformer T,may be located ywherever desired, it is preferred, as indicated in Figs.9 and l0, that they be assembled in a portable unit within a control box53 having a detachable cover 54 provided with a carrying handle 55.

To a side wall of the box 53 is secured a socket 56 into which isadapted to be inserted a plug to which the service wires 43 and 44 areconnected. To the posts 57 is attached the plate of insulating material58 upon which is mounted the fuse 59 through which all current issupplied to the transformer T, valves V, Vl and motor M.

Upon the bottom of the box 53 are secured thc transformer T and thesockets 60 for the valves V and V1.

The socket A is mounted-upon a side wall of the box, part disposed.within and the remainder outside of the box.

The discharge passage or casing 61 of the pump P connects with thesocket A. andat any suitable point, as 62, is provided a hole for outletof a portion of the air pumped into the interior of the box for coolingpurposes. In a side of the box adjacent the intake of the pump P areprovided apertures 63 for entry of air to the pump through any snitableair cleaning or screening structure, not shown. In another side wall maybe provided apertures 64 to permit egress of the cooling air enteringthe box from the aperture 62. The valve structure V, V1 is disposed inthe path of the air issuing from hole 6.2 and escaping through theaperturesc 64, and is cooled thereby. vSome of the air issuing from thehole 62 passes in contact also with the motor M and transformer T,cooling them. The motor M is mounted on the side of the pump P or uponthe bottom of the box 53, and has its arma-ture shaft directly coupledto the rotor or impeller of the pump P.

As illustrated in Fig. 11, a reciprocating motor system embodying myinvention comprises a reciprocating motor or hammer unit 66 and aportable power plant including an alternating current generator 67, asmall exciter generator 68 for exciting the field winding 69 of thegenerator 67, an air blower 70, a prime mover` 71, which is illustratedfor simplicity as an internal combustion engine, and a control box 72.The electric energy .from the generator 67 and the air current from theblower 70 are supplied to the control box 72 containing apparatus forcontrol-y ling the energization of the reciprocating motor 66. Theelectric energy and the currentof air are transmitted from the controlbox 72 to the motor 66 through conducting means such as a cable 73 whichis provided with a plug connector 74 to permit connection readily to bemade to the apparatus within the control box 72.

Within the control box 72, as diagrammatically illustrated in Fig. l2,are two conductors 75 and 76 extending from the generator 67 atransformer 77, two electric valves V and Vl of the characterhereinbefore ndescribed, and a relay switch 7 8.

The. hammer unit or reciprocating motor comprises the two field oroperating windings 79 and 80 alternately controlled by the valves V andV1 to effect synchronous reciprocating movement of the core member 8l tocause it periodically to impact against a tool 82 of construction anddesign suited to the type of work to be performed.

The motor 66 is provided with a handle 83 and a trigger switch 84controlling delivery of current tothe windings 79 and 80. Thetransformer 77 supplies current for heating the filaments f of thevalves V and V1 which comprise also the anodes a.

Closure of the switch 84 causes closure of the electromagnetic switch 78in the control box 72 to connect the anode or plate of valve V and thefilament of the valve V1 to the conductor 76. Since each of the windings79 and 80 has one terminal connected to the conductor 75, they will bealternately energized through their controlling valves.

By means of the blower 70 a current of air is circulated through andaround the wind,- ings 79 and 8O of .the tamping unit or motor 66sudiciently to prevent the development of excessive temperatures. Theair may be discharged from the. unit 66 through the bore 1 hose 73'hasdisposed within its wall four electrical conductors 85, 86, 87 and 88for connecting the windings and switch of the unit 66 with the controlapparatus in the box 72. The current of air from the blower 70 istransmitted through the central hose passage 89. The hose or cable 73may be provided with an external helically wound armor 73a which may bestrip metal or wire.

As illustrated in Fig. 14, the air-electric coupling or plug and socketarrangement includes the connector 74 which is provided with a pluralityof terminal tips 90 to which the several hose conductors 85-88 areconnected. The end of the cable or hose fits into an opening in the plug74 and is tightly secured to the plug 74 by means of a clamping socket91 and a set screw 92. One end portion of a substantially rigid tube 93of metal or micarta is disposed as shown within the oritice of the hose73 in such manner as to be tightly clamped therein by the clampingsocket 91 and set screw 92.

A socket member 94 for receiving the plug 74 comprises a base 95 securedby bolts 96 upon the exterior of a wall of the control box 72 and uponwhich are supported several contact springs 97 engaged by the terminals90 and insulated from each other and connected to the proper points ofthe circuit within the control box 72. Directly behind the contactsprings and within the box 72 is disposed a socket member 98 arranged toreceive the other end portion of tube 93 to permit a fairly tightconnection for air transmitted from the blower 70 to the hose 73. Thesocket 98 comprises a tube 99 proceeding from the blower i to the box72, a ring or gasket 100 of resilient material such as rubber, and acasing 101 disposed to enclose the ring and to support it. A guide 102constitutes part pf the casing 101 to guide the tube 93 so that 1t w1llabut against the resilient ring 100.' The structure comprising thecasing 101 and the ring 100 .is supported directly behlnd the contactsprings 97 by brackets 103 secured by the bolts 96. 4 c

By recourse to. a structure of the reciprp rating motor of the characterindicated 1n Fig. 1 the air cooling is of enormous advantage in that theratio of the weight of the reciprocating motor to its power or the workdonc upon the tool 21 is reduced to less than 50% while restricting thetemperature rise to about 50 C. or less. This improved weight to powerratio is practically that of reciprocating motors or hammers operated bycornpressed air. v

Air at relatively low pressure may be utllized. Pressure of the air asdelivered to the tube or passage 32 of the reciprocating motor may be ofthe order of one pound per square inch, and is generally of the order ofone-half pound per square inch or less. Theicross sec- I tion and lengthofthe cooling medium passages within the reciprocating motor are suchthat at such pressures there is utilized one cubic foot of air (atatmospheric pressure) per' yminute for each to 35 watts lost in thewinding and field structure of the reciprocat- 1ng motor. v i

When the tool operated by the reciprocating motor is a drill and it isdesired to remove material from the hole by cooling air exhausted fromthe reciprocating motor, as may be the case in an arrangement of thecharacter of Figs. 11 and 15, the pressure of air supplied to thereciprocating motor may be of the order of 5 to l5 pounds per squareinch, depending upon the depth of hole and nature Yof material to beremoved.

lIt shall be understood, however, that my invention is not limited tothe foregoing proportions, pressures, ratios etc., since variousfeatures of my invention are new and useful without regard to suchlimitations.

What I claim is:

l. A reciprocating motor comprising a casing, circumferentially andaxially spaced groups of field laminas, a reciprocating core member, afield winding having within it an axially extending passage for coolingmedium, and a housing on one end of said casing having a chambercommunicating with said passage through the spaces between groups oflaminas.

2. A reciprocating motor comprising a casing, circumferentially andaxially spaced groups of field laminas, a reciprocating core member, afield winding having within it an axially extending passage for coolingmedium and spaced from said casing to form a second passage for coolingmedium, said passages adapted to conduct cooling medium in paralleltherethrough, and a housing on one end of said casing affording fluidconnections with said passages through the spaces between groups oflaminae.

3. A reciprocating motor comprising a tubular member, a core memberreciprocating therein, circumferentially and axially spaced groups offield lamin, a field winding surrounding and spaced from said tubularmember to form a passage for cooling medium communicating with thespaces between groups of laminas, and means for conducting coolingmedium to said spaces between groups of lamin.l

4. A reciprocating motor comprising a tubular'member, a core memberreciprocating therein, circumferentially, and axially spaced groups offield laminas, a plurality of field windings separated by groups oflaminae and spaced from said tubular member to form passages for coolingmedium in communication with each other through the spacesbevcumferentially and axially tween said last named groups of l'aminae,and means for conducting cooling medium in parallel through saidpassages.

5. A reciprocating motor comprising a tubular member, a core membertherein, cirspaced groups of field laminee, a casing, a pluralityofwind-Y ings separated by groups of lamin and spaced from said casing andfrom said tubular member to form a plurality of parallel passages forcooling medium, andmeans for conducting cooling medium in parallelthrough said passages.

6. A reciprocating motor comprising a tubular member, a core membertherein, circumferentially and axially spaced groups of field laminae, acasing, a plurality of windings separated by groups of: laminas andspaced from said casing and 'from said tubular member to form passagesfor cooling medium, a housing rigidly mounted with respect to saidcasing having a chamber communicatingwith said passages, and means forconducting cooling medium to said chamber.

'7. A reciprocating motor comprising a tubular member having slots, acore member reciprocating therein, eircumferentially and axially spacedgroups of field laminae, a field winding surrounding and spaced fromsaid tubular member to form a passage for cooling medium, non-conductingmeans closing communication between said passage and the interior ofsaid tubular member through said slots, and means for conductingcooling'medium to said passage.

8. A reciprocating motor comprising a tubular member, a core memberreciprocating therein, circumferentially and axially spaced groups offield laminee having poles extending through the wall of said tubularmember, a field winding surrounding and spaced from said tubular memberto form a passage for cooling medium, said tubular member having slotsdisposed between said poles, means for preventing connnunication throughsaid slots between said passage and the interior .of said tubularmember, and means for conducting cooling medium to said passage.

9. A reciprocating motor comprising field members, a reciprocating coremember, a casing, a field winding surrounding said core member andspaced therefrom and from said casing to form passages for coolingmedium.,

a handle member rigidly secured with respect to said casing and having achamber communicating with said passages, and a conduit for coolingmedium attached to said handle giember and communicating with saidvcham- 10\. A reciprocating motor comprising field members, areciprocating core member, -a casing, a field winding surrounding saidcore member and spaced therefrom and from said casingvto form passagesfor cooling medium,

a handle member rigidly secured with respect eating motor wall of saidtubular member, said poles havi ing a greater degree of hardness thanthe remaining portions of said field members, 'a field winding, and areciprocating core member Within said tubular member bearing upon saidhardened poles.

12. A reciprocating motor comprising a tubular member, longitudinallyand axially spaced groups of field laminae having hardened pole tipsextending throughthe wall of said tubular member., and a reciprocatingcore member within said tubular member bearing upon said hardenedpoletips.

13. In combination, a portable reciprocating motor comprising fieldmembers, a reciprocating core member, afield winding,

structure for bringing cooling medium into heat-absorbing relation withrespect to the motor parts, a pump remote from said motor l'fordelivering cooling medium thereto, an

electric motor Jfor driving said pump, and a switch on'saidreciprocating motor for controlling supply of current to said fieldwindingand to said pump-driving motor.

14. In combination, a portable reciprocomprising field members, areciprocating core member, a field winding, structure for bringingcooling medium into heat--absorbing relation with respect to the motorparts, a ypump for cooling medium remote from said motor, a source ofelectric 3 current, a control box, a connection from said control box tosaid reciprocating motor 'for delivering cooling medium thereto, andelectrical connections from said control box to saidffield Windingincorporated in said firstnamed connection.

15. In combination, a portable recipro- A eating motor comprising fieldmembers, a reciprocating core member, a field winding, structure Yheat-absorbing relation with respect to the motor parts, a source ofcurrent, a control box. a pump in said control box, a connection fromsaid control box for delivering cooling mefor bringing cooling mediuminto dium to said reciprocating motor, an electric j motor in saidcontrol box driving said pump. and electrical connections 'from saidcontrol box to said field winding incorporated in said first-namedconnection.

`16. In combination, a portable reciprocating motor comprising fieldmembers, a reciprocating cor`e member, a field winding, structure lforbringing cooling medium into heat-absorbing relation with respect to themotor parts, a source of current, a control for supplying a coolingmedium to thetool,

box, a pump in said control box, a connection from said control box fordelivering cooling medium to said reciprocating motor, an elec,- tricmotor in said control box driving said pump, electrical connectionsfrom'said con-- trol box to said field winding, and a switch on saidreciprocating motor controlling the circuitof said field winding and ofsaid motor in the control box.4 17. In combination, a portablereciproeating motor comprising field members, a reciprocating coremember, a field winding,

structure for bringing cooling medium into heat-absorbing relation withrespect to the motor parts, a sourceof alternating current,

a control box, electric valve structure in saidV ymotor parts, a sourceof electric current, a

control box, electric valve structure therein, a hose structureextending from said control box to said reciprocating motor, conductorsin said hose connecting said valve structure and field winding incircuit with said source of current, and a pump delivering coolingmedium through said hose toy said reciprocating motor.

19. The combination with a manuallyr portable electric tool and arelatively7 stationary ysource of electric energy therefor, of means andcircuit controlling means for rendering said cooling means effective totransmit the cooling medium to the tool so long as the tool .isenergized from said source of energy, said' circuit controlling meansadapted to simultaneously de-energize said Atool and cooling means. c

20. The combination with a percussive tool of the reciprocating motortype, a source of a1- ternating current energy therefor and meansassociated therewith to control the transmis sion of energy to the tool,ofmeans for supplying a cooling medium for the tool comprising an airblower, a flexible cable for transmitting the cooling medium and theelectric energy to the tool, and a unitary connector vassociated withthe cable for simultaneously effecting electrical connection between thetool and the control means, andalso between the tool and the air blower.

21. A reciprocating motor comprising a field winding, individual groupsof field ,mem-

bers radially disposed with 'respect to a central tubular member, areciprocating core member adapted to move within said tubular member,said groups of field members form ing with the inner surface of saidfield winding a plurality of passages extending axially of said windingadapted to conduct a cooling medium therethrough, and means forconducting cooling medium Vto said passages.

2:2. reciprocating motor comprising individual groups of field membersradially disposed with respect to a tubular member, a reciprocatingcoremember adapted to move within said tubular member, a field windingsurrounding and spaced from said tubular member, means for securingindividual groups of field members with respect to said tubular member,said securing means being axially aligned with and approximately equalin width to said groups for permitting unrestricted passage of a coolingmedium between p the inner surface of said field winding and theconverging portions of said field members, and means for conductingcooling medium to said passages.

23. A reciprocating motor comprising individual groups of field membersdisposed radially with respect to a central tubular member,la fieldwinding surrounding and.

spaced from said tubular member, said field members having polesextending axially of said winding, a plurality of clamping means forengaging and securing said poles with respect to said 'tubular member,said clamp- 'ing means being comparatively narrow with respect tothecircumference of saidtubular member thereby permitting substantiallyunrestricted fiow of a cooling medium through passages formed by theinner surface of said field winding and the converging portions of saidfield members, and means for conducting cooling medium to said passages.

24. A portable reciprocating motor comprising av tubular member, a coremember reciprocating therein, a casing, field magnet structure disposedbetween said tubular mem-v ber and saidl casing and comprising a fieldwinding surrounding said member and spaced therefrom and from saldcasingnto form passages for cooling medium, a housing rigidly secured tosaid casing at one end thereof having a chamber communicating with saidpassages, and means for conducting cooling medium directly to saidchamber before admission of the same to said passages.

25. In apparatus of` the character described, an element supported forreciprocatory movement, electro-magnetic means for Iimparting suchmovement to said element,

electrical-supply.connections for said electromagnetic means, saidapparatus provided with a passage providing for unidirectional flow ofcooling fluid through said apparatus wherein such fluid flows into oneend portion of said apparatus and is discharged from the other endIportion of the same, means disposed exteriorally with respect to saidapparatus and operable to induce such fluid-j iow, and means providingan operating connection between said apparatus and said second-namedmeans, said third-named means providing a protective casing for said pelectrical-supply connections.

26. In apparatus o the character described, an element supported 'forreciprocatory movement, lectro-magnetic meansfor imparting such movementto said element, said apparatus provided with a passage providing forunidirectional flow of cooling fluid through said apparatus dwhereinsuch duid Y flowsinto one end portion'of saidv apparatus and isdischarged from the other end portion of the same, and structure formingpart of said apparatus and disposed at and constitilting one ofsaid endportions thereof and,

formed to provide a hand-grip for manual- Y manipulation of said.apparatus, said structure provided with a passage 'forming part of thepassage foresaid. v

2'?. ln apparatus of the character described, a primary electric motor,currentrectifying means for supplying said motor, and means commorF tosaid motor and said ciprocating motor, means for impelling medium forcooling said valve structure, and a motor common to and driving saidgenerator and impelling means. l

CARL S. WEYANDT.

29'. The combination with a source of alternating current, pf a portablemotor, valve structure through which said motor is energized from saidsource, a separate unit comprising an auxiliary motor and means forimpelling cooling medium driven by said auxiliary motor, and, aconnection for conducting cooling medium from said unit to said portablemotor, said 4valve structure cooled by medium impelled by'said means.

`30. They combination with a source vof al-Y ternating current, ofaportable motor, valve structure through which said motor is ener--gized from said source, a` separate unit oomprising an auxiliary motorand means for inipelling cooling medium driven by said auxiliary motor,said valve structure included in said unit and cooled by mediumimpelledby said means, and connections extending froml said valve structure tosaid portable motor.

31, The combination' with a reciprocating motor, of valve structure, anda unitseparate from said reciprocating motor comprising an alternatingcurrent generator supplying cur-s,

rent through said valve structure to said relooV

